Not corn but I use soy beans here in Louisiana. I have 12 - 30 gallon black plastic drums with cam lock tops. I have some bean that are almost 2 years old left in 1 drum and they look and smell just like the day they were placed in the drums. I have a 30x60 insulated shop (no ac), so its not in direct sunlight or cold temps. No moisture can get in them either.
